[rhelv6-list] Problems resizing tmpfs under RHEL6

[carlopmart]

On 02/22/2011 02:44 PM, Benjamin Franz wrote:
> On 02/21/2011 02:23 PM, carlopmart wrote:
>> On 02/21/2011 11:10 PM, Benjamin Franz wrote:
>>>
>>> I have /dev/shm set to 8g on one of my machines using 'size=8g'.
>>>
>>
>> Can you show your fstab entry for tmpfs Bejamin??
>
> tmpfs /dev/shm tmpfs size=8g 0 0
>
> Note: This is on a CentOS5.5 machine. I haven't tried it on a RH6 machine.
>

Ok, and yes. Under centos 5 or rhel5 all works as expected (i have another rhel5 
host and tmpfs works ok), but under rhel6 not. For example.

My fstab:

#
# /etc/fstab
# Created by anaconda on Sun Feb 20 14:33:14 2011
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=ea53b08b-1557-4e37-b88a-e3b672bcf569 /                       ext4    defaults 
       1 1
/dev/mapper/cryptvol-datavol /export/data            ext4    defaults        1 2
/dev/mapper/luks-ac5ed44c-f316-4b3a-9b2d-c3c15228ce04 /export/home            ext4 
   defaults        1 2
UUID=d16b644b-020f-4693-bc21-e5d9aa9b8e7b swap                    swap    defaults 
       0 0
tmpfs                   /dev/shm                tmpfs   size=2g	        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0

Output of mount command:

[carlos at rhel6srv tmp]$ mount
/dev/sda1 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw,size=2g)
/dev/mapper/cryptvol-datavol on /export/data type ext4 (rw)
/dev/mapper/luks-ac5ed44c-f316-4b3a-9b2d-c3c15228ce04 on /export/home type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)

So far, everything is fine. But when I execute df command:

[carlos at rhel6srv tmp]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             7.9G  2.7G  4.9G  36% /
tmpfs                 1.5G  312K  1.5G   1% /dev/shm
/dev/mapper/cryptvol-datavol
                        63G  9.6G   51G  17% /export/data
/dev/mapper/luks-ac5ed44c-f316-4b3a-9b2d-c3c15228ce04
                        16G  3.7G   12G  25% /export/home

  .. shows only 50% of memory for tmpfs. Weird, right??


-- 
CL Martinez
carlopmart {at} gmail {d0t} com